Yesterday marked 100 years since the end of the First World War. The Washington Post’s Monkey Cage blog used the occasion to publish an excellent commentary, based on a longer academic journal article, by political scientists Alexander Lanoszka and Michael A. Hunzeker. They argue that the Great War could have actually ended long before the eleventh hour of the eleventh day of the eleventh month of 1918. Two years earlier, in December 1916, both “Germany and the United States issued peace overtures” that, if heeded, “could have spared countless lives and have helped Europe escape the financial ruin and deep‐​seated animosity that produced World War II,” Lanoszka and Hunzeker explain. “Unfortunately, the Entente — Britain, France and Russia — dismissed both offers, and the fighting continued.”

At the time, all sides were facing catastrophic losses, financial insolvency, and a virtual stalemate on the battlefield. An armistice then would have been a great relief to the warring parties. So why did the Entente powers reject peace? According to Lanoszka and Hunzeker, “Honor pushed the Entente to prefer war over peace despite the overwhelming costs and risks…by December 1916, the Entente came to believe the only way to overcome [the] dishonor [of German trangressions against them] was to destroy the German regime itself.”

Honor is not “a relic of a bygone era in international relations,” the authors conclude. Indeed, it is still very much with us.

Sociologists argue that honor is crucial to group self‐​esteem, involving an emotional investment in how groups define themselves and their place in social hierarchies. Honor leads actors to believe that others must respect these identities. It can enhance cooperation when mutual respect exists, but encourage severe escalation and undercut conflict resolution when it does not.

Accordingly, when identity faces an external threat, actors feel an intense psychological need to salvage their honor. To restore besmirched honor, either the transgressor apologizes or the victim punishes. The longer the transgressor refuses to apologize and resists punishment, the more the victim will dig in and perhaps even risk dying for honor’s sake.

Threats to honor can thus undermine rational behavior and make wars longer. Rationality means that an actor objectively assesses available information, selects which goals it will pursue and picks the most efficient and risk averse way to do so. However, when honor is at stake, leaders might begin to ignore disconfirming evidence, prioritize honor over survival and adopt strategies based on hope, not efficiency.

I recently published an article in The Washington Quarterly arguing that concerns over America’s honor, status, and prestige discourage a much‐​needed shift in U.S. foreign policy away from the costly and counterproductive grand strategy of primacy and toward retrenchment. As the American diplomat James B. Foley put it, “public support for U.S. global leadership [since WWII] has been sustained by a romantic faith in America’s overseas mission – a kind of internationalized Manifest Destiny” that makes any suggestion of retrenchment “psychologically deflating.” Decision‐​makers thus remain committed to an extraordinarily activist foreign policy despite the dire costs, high risks, and the fact that America’s core security would remain intact with a much less ambitious set of strategic objectives.

In Paris this weekend, world leaders commemorated the centennial. French President Emmanuel Macron rebuked  the brutish nationalism of the early 20th century that helped lead to the bloodbath, while indirectly (though not subtly) condemning President Trump’s hardline nationalist worldview as a dangerous throwback to that tragic era. Sure enough, Trump is very much preoccupied with honor and prestige, and it shows in his foreign policy. Much has been made of how well Trump fits into the “Jacksonian tradition” in U.S. foreign policy. According to the political scientist Walter Russel Mead, who coined the term in his 2001 book Special Providence, the Jacksonian tradition features “a deep sense of national honor” that “must be acknowledged by the outside world” and must be defended, including by going to war over “great things and small.”

Trump rose to power complaining about “a tremendous lack of respect for our country,” a phrase he repeated countless times on the campaign trail. The sentiment reaches back decades. In a 1988 interview, when asked what his political platform would be should he run for office, Trump boiled it down to a single word: “Respect.” He added that our adversaries are “beating us psychologically, making us look like a bunch of fools.” Even more explicitly, in a 1990 interview with Playboy magazine, Trump explained that America was “suffering from a loss of respect,” adding that “people need ego, whole nations need ego. I think our country needs more ego” because our leaders have let other countries “literally out‐​egotise this country.”

“The key to understanding Trump’s foreign policy outlook,” according to the political scientist Reinhard Wolf, “lies in his extreme attention to symbolism,” where “questions of substance are eclipsed by an obsession with status and respect…[F]or Trump, America First is not so much about advancing the national interest measured in terms of material wealth or physical survival. It is, first and foremost, about the United States becoming the undisputed ‘number one’ again, and being treated with due respect.”

Critics of Trump’s foreign policy often decry his supposedly isolationist impulses and his withdrawal from the world stage. However, though the administration has pulled out of several international agreements, America’s global military commitments have not shrunk. In some ways, Trump has expanded them. He has overseen increased military spending, the expansion of NATO, higher troop deployments to Europe and the Middle East, and a less restrained use of air power and other uses of force in multiple countries under dubious legal authority. Trump has not withdrawn from a single one of America’s 60‐​plus security commitments and, despite a near universal regonition that the war in Afghanistan is unwinnable, he has surged troops there to finish an unachievable mission.

As with the Entente powers, intangible psychological motivations are driving U.S. militarism at the expense of more material economic and security interests. In 1916, that cost Europe dearly. In 2018, it’s costing America dearly, too.